
 /* MD5加密开始 */
 var hexcase = 0; 
 var b64pad  = "";
 var chrsz   = 8;
 
function hex_md5(s){ 
	 return binl2hex(core_md5(str2binl(s), s.length * chrsz));
}
 
function binl2hex(binarray)
{
   var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
   var str = "";
   for(var i = 0; i < binarray.length * 4; i++)
   {
     str += hex_tab.charAt((binarray[i>>2] >> ((i%4)*8+4)) & 0xF) +
            hex_tab.charAt((binarray[i>>2] >> ((i%4)*8  )) & 0xF);
   }
   return str;
}

function core_md5(x, len)
{
  x[len >> 5] |= 0x80 << ((len) % 32);
  x[(((len + 64) >>> 9) << 4) + 14] = len;

  var a =  1732584193;
  var b = -271733879;
  var c = -1732584194;
  var d =  271733878;

  for(var i = 0; i < x.length; i += 16)
  {
    var olda = a;
    var oldb = b;
    var oldc = c;
    var oldd = d;

    a = md5_ff(a, b, c, d, x[i+ 0], 7 , -680876936);
    d = md5_ff(d, a, b, c, x[i+ 1], 12, -389564586);
    c = md5_ff(c, d, a, b, x[i+ 2], 17,  606105819);
    b = md5_ff(b, c, d, a, x[i+ 3], 22, -1044525330);
    a = md5_ff(a, b, c, d, x[i+ 4], 7 , -176418897);
    d = md5_ff(d, a, b, c, x[i+ 5], 12,  1200080426);
    c = md5_ff(c, d, a, b, x[i+ 6], 17, -1473231341);
    b = md5_ff(b, c, d, a, x[i+ 7], 22, -45705983);
    a = md5_ff(a, b, c, d, x[i+ 8], 7 ,  1770035416);
    d = md5_ff(d, a, b, c, x[i+ 9], 12, -1958414417);
    c = md5_ff(c, d, a, b, x[i+10], 17, -42063);
    b = md5_ff(b, c, d, a, x[i+11], 22, -1990404162);
    a = md5_ff(a, b, c, d, x[i+12], 7 ,  1804603682);
    d = md5_ff(d, a, b, c, x[i+13], 12, -40341101);
    c = md5_ff(c, d, a, b, x[i+14], 17, -1502002290);
    b = md5_ff(b, c, d, a, x[i+15], 22,  1236535329);

    a = md5_gg(a, b, c, d, x[i+ 1], 5 , -165796510);
    d = md5_gg(d, a, b, c, x[i+ 6], 9 , -1069501632);
    c = md5_gg(c, d, a, b, x[i+11], 14,  643717713);
    b = md5_gg(b, c, d, a, x[i+ 0], 20, -373897302);
    a = md5_gg(a, b, c, d, x[i+ 5], 5 , -701558691);
    d = md5_gg(d, a, b, c, x[i+10], 9 ,  38016083);
    c = md5_gg(c, d, a, b, x[i+15], 14, -660478335);
    b = md5_gg(b, c, d, a, x[i+ 4], 20, -405537848);
    a = md5_gg(a, b, c, d, x[i+ 9], 5 ,  568446438);
    d = md5_gg(d, a, b, c, x[i+14], 9 , -1019803690);
    c = md5_gg(c, d, a, b, x[i+ 3], 14, -187363961);
    b = md5_gg(b, c, d, a, x[i+ 8], 20,  1163531501);
    a = md5_gg(a, b, c, d, x[i+13], 5 , -1444681467);
    d = md5_gg(d, a, b, c, x[i+ 2], 9 , -51403784);
    c = md5_gg(c, d, a, b, x[i+ 7], 14,  1735328473);
    b = md5_gg(b, c, d, a, x[i+12], 20, -1926607734);

    a = md5_hh(a, b, c, d, x[i+ 5], 4 , -378558);
    d = md5_hh(d, a, b, c, x[i+ 8], 11, -2022574463);
    c = md5_hh(c, d, a, b, x[i+11], 16,  1839030562);
    b = md5_hh(b, c, d, a, x[i+14], 23, -35309556);
    a = md5_hh(a, b, c, d, x[i+ 1], 4 , -1530992060);
    d = md5_hh(d, a, b, c, x[i+ 4], 11,  1272893353);
    c = md5_hh(c, d, a, b, x[i+ 7], 16, -155497632);
    b = md5_hh(b, c, d, a, x[i+10], 23, -1094730640);
    a = md5_hh(a, b, c, d, x[i+13], 4 ,  681279174);
    d = md5_hh(d, a, b, c, x[i+ 0], 11, -358537222);
    c = md5_hh(c, d, a, b, x[i+ 3], 16, -722521979);
    b = md5_hh(b, c, d, a, x[i+ 6], 23,  76029189);
    a = md5_hh(a, b, c, d, x[i+ 9], 4 , -640364487);
    d = md5_hh(d, a, b, c, x[i+12], 11, -421815835);
    c = md5_hh(c, d, a, b, x[i+15], 16,  530742520);
    b = md5_hh(b, c, d, a, x[i+ 2], 23, -995338651);

    a = md5_ii(a, b, c, d, x[i+ 0], 6 , -198630844);
    d = md5_ii(d, a, b, c, x[i+ 7], 10,  1126891415);
    c = md5_ii(c, d, a, b, x[i+14], 15, -1416354905);
    b = md5_ii(b, c, d, a, x[i+ 5], 21, -57434055);
    a = md5_ii(a, b, c, d, x[i+12], 6 ,  1700485571);
    d = md5_ii(d, a, b, c, x[i+ 3], 10, -1894986606);
    c = md5_ii(c, d, a, b, x[i+10], 15, -1051523);
    b = md5_ii(b, c, d, a, x[i+ 1], 21, -2054922799);
    a = md5_ii(a, b, c, d, x[i+ 8], 6 ,  1873313359);
    d = md5_ii(d, a, b, c, x[i+15], 10, -30611744);
    c = md5_ii(c, d, a, b, x[i+ 6], 15, -1560198380);
    b = md5_ii(b, c, d, a, x[i+13], 21,  1309151649);
    a = md5_ii(a, b, c, d, x[i+ 4], 6 , -145523070);
    d = md5_ii(d, a, b, c, x[i+11], 10, -1120210379);
    c = md5_ii(c, d, a, b, x[i+ 2], 15,  718787259);
    b = md5_ii(b, c, d, a, x[i+ 9], 21, -343485551);

    a = safe_add(a, olda);
    b = safe_add(b, oldb);
    c = safe_add(c, oldc);
    d = safe_add(d, oldd);
  }
  return Array(a, b, c, d);
}

function str2binl(str)
{
  var bin = Array();
  var mask = (1 << chrsz) - 1;
  for(var i = 0; i < str.length * chrsz; i += chrsz)
    bin[i>>5] |= (str.charCodeAt(i / chrsz) & mask) << (i%32);
  return bin;
}

function md5_cmn(q, a, b, x, s, t)
{
  return safe_add(bit_rol(safe_add(safe_add(a, q), safe_add(x, t)), s),b);
}
function md5_ff(a, b, c, d, x, s, t)
{
  return md5_cmn((b & c) | ((~b) & d), a, b, x, s, t);
}
function md5_gg(a, b, c, d, x, s, t)
{
  return md5_cmn((b & d) | (c & (~d)), a, b, x, s, t);
}
function md5_hh(a, b, c, d, x, s, t)
{
  return md5_cmn(b ^ c ^ d, a, b, x, s, t);
}
function md5_ii(a, b, c, d, x, s, t)
{
  return md5_cmn(c ^ (b | (~d)), a, b, x, s, t);
}

function safe_add(x, y)
{
  var lsw = (x & 0xFFFF) + (y & 0xFFFF);
  var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
  return (msw << 16) | (lsw & 0xFFFF);
}
function bit_rol(num, cnt)
{
  return (num << cnt) | (num >>> (32 - cnt));
}
/* MD5加密结束 */

/*js加密解密字符串自定义密码因子*/
function encrypt(str, pwd) { 
	 if (pwd == null || pwd.length <= 0) {
		 alert("请输入密码来加密信息！");
			return null;
		}
		var prand = "";
		for (var i = 0; i < pwd.length; i++) {
			prand += pwd.charCodeAt(i).toString();
		}
		var sPos = Math.floor(prand.length / 5);
		var mult = parseInt(prand.charAt(sPos) + prand.charAt(sPos * 2)
				+ prand.charAt(sPos * 3) + prand.charAt(sPos * 4)
				+ prand.charAt(sPos * 5));
		var incr = Math.ceil(pwd.length / 2);
		var modu = Math.pow(2, 31) - 1;
		if (mult < 2) {
			alert("算法不能找到合适的哈希值。请选择一个不同的密码。");
			return null;
		}
		var salt = Math.round(Math.random() * 1000000000) % 100000000;
		prand += salt;
		while (prand.length > 10) {
			prand = (parseInt(prand.substring(0, 10)) + parseInt(prand
					.substring(10, prand.length))).toString();
		}
		prand = (mult * prand + incr) % modu;
		var enc_chr = "";
		var enc_str = "";
		for (var i = 0; i < str.length; i++) {
			enc_chr = parseInt(str.charCodeAt(i)
					^ Math.floor((prand / modu) * 255));
			if (enc_chr < 16) {
				enc_str += "0" + enc_chr.toString(16);
			} else
				enc_str += enc_chr.toString(16);
			prand = (mult * prand + incr) % modu;
		}
		salt = salt.toString(16);
		while (salt.length < 8)
			salt = "0" + salt;
		enc_str += salt;
		return enc_str;
 }
 
 function decrypt(str, pwd) { 
	 if (str == null || str.length < 8) {
		alert("长度太短，解密失败！");
			return;
		}
		if (pwd == null || pwd.length <= 0) {
			alert("请输入密码来解密信息。");
			return;
		}
		var prand = "";
		for (var i = 0; i < pwd.length; i++) {
			prand += pwd.charCodeAt(i).toString();
		}
		var sPos = Math.floor(prand.length / 5);
		var mult = parseInt(prand.charAt(sPos) + prand.charAt(sPos * 2)
				+ prand.charAt(sPos * 3) + prand.charAt(sPos * 4)
				+ prand.charAt(sPos * 5));
		var incr = Math.round(pwd.length / 2);
		var modu = Math.pow(2, 31) - 1;
		var salt = parseInt(str.substring(str.length - 8, str.length), 16);
		str = str.substring(0, str.length - 8);
		prand += salt;
		while (prand.length > 10) {
			prand = (parseInt(prand.substring(0, 10)) + parseInt(prand
					.substring(10, prand.length))).toString();
		}
		prand = (mult * prand + incr) % modu;
		var enc_chr = "";
		var enc_str = "";
		for (var i = 0; i < str.length; i += 2) {
			enc_chr = parseInt(parseInt(str.substring(i, i + 2), 16)
					^ Math.floor((prand / modu) * 255));
			enc_str += String.fromCharCode(enc_chr);
			prand = (mult * prand + incr) % modu;
		}
		return enc_str;
 }
 /*js加密解密字符串自定义密码因子*/

  module.exports = {
    hex_md5: hex_md5
  }
